Fix reading of empty parameter values
Fix reading of empty parameter values

When a group parameter has empty value (like uninitialized cpuset.cpus),
libcgroup does not return this parameter value - it returns
ECGROUPVALUENOTEXIST instead.

I think reading whole parameter file instead of just '%s' is the right thing
to do - it helps also with multiline values, like cpuacct.stat.

Signed-off-by: Jan Safranek <a7f4b96ffdd515ecef00f117294da18555749b0b@redhat.com>

rafalmiel/libcg,jrfastab/Linux-cgdcbxd,rafalmiel/libcg,rafalmiel/libcg,jrfastab/Linux-cgdcbxd,jrfastab/Linux-cgdcbxd,rafalmiel/libcg,jrfastab/Linux-cgdcbxd